(n.) An ultimate particle of matter not necessarily indivisible; a molecule.
(n.) A constituent particle of matter, or a molecule supposed to be made up of subordinate particles.
(n.) The smallest particle of matter that can enter into combination; one of the elementary constituents of a molecule.
(n.) Anything extremely small; a particle; a whit.
(v. t.) To reduce to atoms.
Example Sentences:
(1) It has been conformed that catalase from bovine liver eliminates only the pro R hydrogen atom from ethanol.
(2) The results demonstrated that K2PtCl4 was bound to a greater degree than CDDP in this system with 3-5 and 1-2 platinum atoms respectively, bound per transferrin molecule.
(3) Richard Bull Woodbridge, Suffolk • Why does Britain need Chinese money to build a new atomic generator ( Letters , 20 October)?
(4) The bond distances of Cu to Cl(1), Cl(2), N(3) and N(3') atoms are 2.299 (1), 2.267 (1), 1.985 (4) and 1.996 (3) A, respectively.
(5) The common atoms of the [3Fe-4S] and [4Fe-4S] cores agree within 0.1 A; the three common cysteinyl S gamma ligand atoms agree within 0.25 A.
(6) This result was confirmed by atomic absorption spectroscopy, which indicated a stoicheiometry for copper and manganese of approx.
(7) The inter-molecular similarity measure used is the number of atoms in the 3-D common substructure (CS) between the two molecules which are being compared.
(8) The risks are determined, mainly by expert committees, from the steadily growing information on exposed human populations, especially the survivors of the atomic bombs dropped in Japan in 1945.
(9) All N and O atoms except N(3) and O(4') participate in a three-dimensional hydrogen-bonding system.
(10) This suggestion is supported by EPR studies, which show that the iron atoms in Fe(III)L-globin are in two low electronic states.
(11) The molar refractivity has been shown to be a superior parameter for the description of the activity of sulphonamides than the sum of electronegativities of atoms making up a heterocyclic substituent in the sulphonamide molecule and molecular weight of the substituent.
(12) Binding to HSA occurs primarily with the imidazolidine and thiazolidine groups of levamisole as it has been demonstrated by selective changes in the relaxation times and the chemical shifts of the protons attached to the carbon atoms.
(13) Each repeat unit contains thirty amino acids and is thought to bind a zinc atom using two cysteines and two histidines as ligands.
(14) NADP+ bound at the C8 atom in the adenine moiety proved to be the most efficient ligand whereas that bound at the C3 atom of the ribose moiety was relatively inefficient.
(15) This structure is further characterized by approaches of both the carbonyl and the furan O atoms to ring H atoms with separations which are slightly less than the sum of the relevant van der Waals radii.
(16) The magnitude of improvement achieved is dependent upon field size, SSD, the atomic number of the foil material, and foil thickness.
(17) For the liver enzyme, the logarithm of the inhibition constant was linearly related to the number of carbon atoms in the saturated fatty acids whereas the muscle enzyme, which was generally more strongly inhibited, showed a nonlinear dependence.
(18) Results obtained from a such study are here compared with levels obtained from a comparative determination of the metals in the mosses by three other techniques: Differential pulse anodic stripping voltammetry (DPASV), Direct current plasma (atomic emission) spectroscopy (DCPS) and X-ray fluorescence (XRF) spectroscopy.
(19) It was hypothesized that the observed activity variation of the paracetamol analogues was based on the relative abilities of these compounds to undergo H atom loss at the phenolic oxygen, and on the relative stabilities of the resulting free-radical species.
(20) The resulting family of structures has a mean backbone rmsd of 0.63 A (N, C alpha, C', O atoms), excluding the segments containing residues 45-59 and 84-88.
Thiophene
Definition:
(n.) A sulphur hydrocarbon, C4H4S, analogous to furfuran and benzene, and acting as the base of a large number of substances which closely resemble the corresponding aromatic derivatives.
Example Sentences:
(1) Quantitative structure activity relationships of 2-amino-3-carboxylic acid ethyl ester thiophene derivatives are described.
(2) Some of the thiophenes and their acetylenic derivatives possess extremely potent phototoxic activities toward membrane-containing viruses.
(3) The compounds were obtained by condensation of appropriate hydrazines with thiophene 2-carboxaldehyde (series 1), thiophene 3-carboxaldehyde (series 2), and 5-nitrothiophene-2-carboxaldehyde (series 3).
(4) The prototype kappa-selective agonist, PD117302 (trans-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl]benzo[b]thiophene-4- acetamide, 2) has been regio- and stereoselectively substituted in the C-4 and C-5 positions of the cyclohexyl ring with the methyl ether and spiro tetrahydrofuran groups.
(5) Since no previously identified genes involved in thiophene metabolism are located in this region, we designated the gene for the 48-kDa protein as thdF.
(6) Among the compounds described are 6-hydroxybenzo[b]thiophene-2-sulfonamide (16) and its acetate ester (23), which are among the most potent ocular hypotensive agents in this class, as assessed in the alpha-chymotrypsinized rabbit.
(7) The normalizing effects of the thiophene compounds on serum phosphorus levels were not significant at the dosages used.
(8) Maximum photo-basophil-histamine-release was 4% with acetylsalicylic acid, 10% with benoxaprofen, 20% with thiophene, 28% with diclofenac, 39% with tiaprofenic acid, 40% with carprofen, 55% with ketoprofen, and not demonstrable with indoprofen.
(9) The more hydrophobic cephalosporins, with a thiophene moiety at the C7 position, were more active than C7-methoxyiminoaminothiazole derivatives against S. aureus H (beta-lactam-susceptible), and compounds with a thioether function at C3 were more active than those with a sulphonyl function at this position.
(10) Several guanidine compounds were synthesized by the reaction of acid chlorides of thiophene and furan with guanidines.
(11) Alpha-terthienyl (alpha-T), a phototoxic thiophene compound isolated from marigolds (Tagetes species), affects cell membranes and does not appear to induce cytogenetic damage.
(12) In a directed search for the best compounds for clinical evaluation, some 150 selected nitroaromatic compounds, representing 6 distinct types, namely, furans, thiophenes, imidazoles, pyrazoles, pyrroles, and triazoles, have been synthesized and tested as hypoxic cell radiosensitisers and bioreductive drugs.
(13) Replacement of ring A by heterocyclic rings (thiophene or pyridine) leads to analogues with only moderate activity.
(14) These results clearly show that all three thiophene systems have potent activity as antihypertensive agents and that 3 and 4 are more potent than 1 or 2 as alpha 1-antagonists in vivo.
(15) A comparative study of the intestinal transport of DL-tryptophan and its 1-methylindole (tryptophan-l-Me) and benzo[b]thiophene (tryptophan-S) analogs has been carried out in vitro, using the everted intestinal sac of the rat and hamster.
(16) Except for cardioselectivity at low doses, the thiophenic analogue of metoprolol behaves in a very similar way as this compound in all the aspects considered in a preliminary pharmacological study.
(17) Six-month chronic oral toxicity studies of 7-chloro-3-[1-(2, 4-dichlorophenyl)-2-(1H-imidazol-1-yl)ethoxy-methyl] benzo[b]thiophene (sertaconazole, FI-7045, CAS 99592-32-2) were carried out in rats and ferrets.
(18) N-(3-dimethylaminopropyl)naphtho[2,1-b]thiophene-4-carboxamide and the 6-substituted methoxy, methyl, fluoro, chloro, bromo, trifluoromethyl, and cyano derivatives have been shown to bind to DNA via intercalation with binding constants in the 35-900 X 10(3) range at 25 degrees C, pH 7, and [Na+] = 0.019M.
(19) Tienilic acid (TA) is metabolized by human liver microsomes in the presence of NADPH with the major formation of 5-hydroxytienilic acid (5-OHTA) which is derived from the hydroxylation of the thiophene ring of TA.
(20) The synthesis of 1-substituted benzothieno[2,3-d]imidazoles and their most suitable synthesis precursor 2-nitro-3-substituted-amino benzo[b]thiophenes is reported.